1. Field of the Invention
The present invention relates to methods and apparatuses for transporting a substrate plate, positioning a substrate plate on a given plane, holding a substrate plate on a holding surface, and exposure processing a substrate plate, and device manufacturing method and device.
2. Description of the Related Art
In recent years, manufacturing of devices (electronic devices) such as semiconductor elements (integrated circuits and the like) or liquid crystal display panels using photolithographic processes has shown an increasing trend toward the use of in-line photolithographic systems comprised by serially-connected processing apparatuses, such as exposure processing and other substrate processing apparatuses, for example, coaters to apply photosensitive coating such as photo-resist on the substrate plate or developers to develop the substrate plate coated with a photosensitive coating.
In this type of photolithographic systems, the main body of an exposure apparatus, a substrate transport apparatus and substrate handling ports are typically placed inside a storage chamber of the exposure apparatus, while, the main body of a coater/developer and a substrate transport apparatus and others are placed inside a chamber of the coater/developer that provides both functions of applying a photo-sensitive material and developing the exposed substrate. A substrate plate, after receiving certain processing inside the coater/developer is transported by the substrate transport apparatus, by way of the substrate handling port connecting both chambers, for processing in the exposure apparatus. In the meantime, an exposed substrate plate is transported back to the coater/developer again in a reverse order to receive additional processing, or transported out of the exposure apparatus to inspection steps and others.
FIG. 18 shows a conventional exposure apparatus. In this exposure apparatus, the substrate plate P is transported by the transport apparatus 300 to the substrate holding apparatus (referred to as substrate holder below) 321 of the exposure apparatus main body 320. The transport apparatus 300 is provided with a robotic arm 301 for holding a substrate plate P; a guide section 302 for freely movably supporting the robotic arm 301; a loader 303 for loading the substrate plate 2 into the exposure apparatus main body 320; and a loader guide section 304 for freely movably supporting the loader 303. The robotic arm 301 and the loader 303 have a vacuum suction cavity for holding the substrate P, and are installed so that they may be moved along the respective guide sections by the action of a rotation motor and a ball screw linked to the rotation motor.
The robotic arm 301 receiving the substrate P through the port PT1 transports the substrate P to a position PS1. At the position PS1, there is provided a first pre-alignment mechanism 305 serving as the first positioning apparatus. The first pre-alignment mechanism 305 is provided with a freely rotatably supported turntable, for example, and a position detection mechanism for detecting the position of the substrate P, and is constructed so as to adjust the position in the rotation direction of the substrate P at the position PS1. After the position of the substrate P is adjusted in the rotation direction, the substrate P is transported by the loader 303 along the loader guide 304 to position PS2. In position PS2, the substrate P is adjusted in the horizontal direction (x-y direction) by the second pre-alignment mechanism 306 serving as the second positioning apparatus, after which, it is held in the substrate holder 321 of the exposure apparatus main body 320. The second pre-alignment mechanism 306 is comprised by a mechanism having a pin that can be moved to abut the substrate P, and is provided as a part of the transport apparatus such as the loader 303, for example. The substrate holder 321 holding the substrate P moves to place the substrate P in the path of illumination light of the exposure apparatus main body 320. Then, illumination light for exposure processing is emitted in the exposure apparatus main body 320 to imprint a circuit pattern fabricated on the mask onto the substrate P. Here, substrate positioning operations using the first and second pre-alignment mechanisms are performed to increase the precision of optical alignment during the actual exposure operation.
The mechanism based on moving the robotic arm 301 by a rotation motor and ball screw arrangement, as described above, tends to increase the size of the overall transport apparatus 300, and therefore, it is necessary to reserve a large installation space. Also, because the system is designed to transfer a substrate P between the robotic arms using vacuum-chucking, the motion is time-consuming and results in lowering the efficiency of manufacturing in some cases. Furthermore, when the transport speed is increased in the transport mechanism based on a rotation motor and ball screw arrangement, there is a danger of generating vibrations and stable transport is difficult to achieve sometimes.
Also, as in the conventional exposure apparatus described above, when it is desired to hold the substrate plate in the substrate holding apparatus, if positioning (pre-alignment) is performed using mechanical motions, vibration from the positioning action is transmitted to the exposure apparatus main body, resulting in a loss of precision in positioning the substrate plate. To improve the productivity of the exposure apparatus, it is often practiced that a plurality of substrate holding apparatuses are prepared so that while one substrate plate on the plate holder is being exposed, the next substrate plate is placed on another plate holder. Therefore, if vibrations are generated by pre-aligning motions, a serious concern is raised that the vibrations are transmitted to mechanical parts to affect the precision of exposure.
Further, as in the conventional positioning apparatus described above, when the substrate plate is positioned mechanically, other problems can also arise such as the necessity for allocating equipment space and devising a complex mechanism. Also, in the conventional exposure apparatuses, after positioning (pre-aligning) the substrate plate mechanically using the pre-alignment mechanism (positioning device), substrate holding is performed by the substrate holding apparatus. For this reason, time is consumed in carrying out mechanical positioning operation itself.
The present invention is provided in view of the background information described above, and a first object of the present invention is to provide a method and an apparatus for transporting the substrate plate efficiently while providing a more compact transport apparatus, and to provide a method and an apparatus for exposure to enable high production efficiency.
The second object of the present invention is to provide a method and an apparatus for positioning the substrate plate to enable to reduce the number of mechanical movements required for positioning so as to control the generation of vibration as well as to make the apparatus more compact and to enable to perform the tasks in shorter time, and a method and an apparatus for holding the substrate plate, and a method and an apparatus for exposing the substrate plate using the apparatuses demonstrated.
The third object of the present invention is to provide a method and an apparatus for exposure processing to enable to produce high precision devices and to improve exposure precision of patterns for actual device, and a method for fabricating high performance devices.
To resolve the topics discussed above, the present invention provides the following structures illustrated in FIGS. 1xcx9c17.
The present method relates to transporting a substrate plate (P) along a transport plane (3) by inducing electric charges in the substrate plate by impressing a voltage on each of a plurality of electrodes (4) arranged along the transport plane (3), and impressing a voltage on each of the plurality of electrodes (4) so as to generate in the plurality of electrodes (4) an electrode charge code identical to a plate charge code induced in the substrate plate (P) to levitate the substrate plate against the transport plane (3) by electrostatic forces; and switching the voltage impressed on each of the plurality of electrodes (4) in accordance with a time interval (Tp) required for producing dielectric polarization in the substrate plate (P).
According to the present method, the substrate plate (P) in the electric charge state is levitated against the transport plane (3) due to electrostatic forces generated by impressing the electrodes (4) with a voltage such that the charge code of the substrate plate (P) is identical to the charge code of the electrodes (4). Then, by switching the voltage impressed on the electrodes (4) arranged along the transport plane (3) in such a way to alter the charge code on each electrode (4), the substrate plate (P) is subjected to a force acting in the transport direction (y-direction). The result is that the substrate plate (P) is transported without contacting the transport plane (3). Because the substrate plate (P) does not contact the transport plane (3), the substrate plate (P) is able to be transported at high speed while suppressing generation of vibration. The present invention thus enables a highly effective transport operation.
In this case, by setting a cycle (Td) for switching the voltage to be shorter than a polarization time constant (T) of the substrate plate, the levitated state of the substrate plate (P) against the transport plane (3) is maintained in a stable manner. That is, because the substrate plate (P) is transported while maintaining the non-contact state, it enables high speed transport while suppressing vibration.
The method is enabled by an apparatus (H) for transporting a substrate plate (P) along a transport plane (3) comprised by: a plurality of electrodes (4) arranged along the transport plane (3); and a control apparatus (9) for inducing electric charges in the substrate plate (P) by impressing a voltage on each of a plurality of electrodes (4) arranged along the transport plane (3), and impressing a voltage on each of the plurality of electrodes (4) so as to generate an electrode charge code identical to a plate charge code induced in the substrate plate (P), and switching the voltage impressed on the plurality of electrodes (4) in accordance with a time interval (Tp) required for producing dielectric polarization in the substrate plate (P).
In this case, a gas supply apparatus (10) for supplying a gas is provided between the substrate plate (P) and the transport plane (3), and by supplying the gas between the substrate plate (P) and the transport plane (3) using the gas supply apparatus (10), the substrate plate (P) is levitated against the transport plane (3) in a stable manner. Therefore, the substrate plate (P) can be transported high speed while maintaining the non-contact state, and a highly effective transport operation is achieved reliably.
In this case, by providing on the transport plane (3), a plurality of second electrodes (5) arranged at right angles (x) to a direction (y) of the arrangement of the electrodes (4) on the transport plane (3), position control is possible in the direction (x) at right angles to the transport direction (y) of the substrate plate (P). It follows that the substrate plate (P) can be transported in a stable manner. In this case, by arranging the second electrodes on both lateral sides of the electrodes, position control becomes even more stable.
The present method for positioning a substrate plate (P) on a specific plane (200) is comprised by: a first step for inducing electric charges in the substrate plate by impressing a voltage on each of a plurality of electrodes (ELD) arranged on the plane (200); a second step for impressing a voltage, that is different than the voltage impressed in the first step, on the plurality of electrodes (ELD) so as to levitate the substrate plate (P) on the plane (200) by electrostatic forces; and a third step for moving the substrate plate (P) in a specific direction while switching the voltage impressed on each of the plurality of electrodes (ELD).
According to the positioning method described above, by applying a specific voltage on each of a plurality of electrodes (ELD) on a electrically charged substrate plate (P), the substrate plate (P) is levitated due to electrostatic forces. Then, by switching the voltage impressed on each of the plurality of electrodes (ELD) arranged along the plane (200), the substrate plate (P) moves to a specific position in the levitated state against the plane (200). Therefore, it enables to position the substrate plate (P) on the specific plane (200) virtually without any mechanical operation. Therefore, the method enables to suppress generation of vibration associated with positioning.
In this case, by switching the voltage in accordance with a time interval required for producing dielectric polarization in the substrate plate, the levitated state of the substrate plate (P) can be maintained in a stable manner.
In this case, a chucking of the substrate plate (P) that has been moved to a specific position on the plane (200) due to electrostatic forces enables the substrate plate (P) to be held reliably in the specific position. Furthermore, because the same electrodes (ELD) are used for the chucking as well as for positioning of the substrate plate (P), the apparatus can be made more compact and processing times can be shortened.
In this case, a gas for levitating the substrate plate (P) may be supplied between the substrate plate (P) and the plane (200). By so doing, levitation of the substrate plate (P) can be carried out in an even more stable manner.
The above method of positioning the substrate plate (P) is carried out by using an apparatus (132) for transporting a substrate plate (P) along a specific plane (200) comprised by: a plurality of electrodes (ELD) arranged along the plane (200); and a control apparatus (9) for inducing electric charges in the substrate plate (P) by impressing a voltage on each of the plurality of electrodes (ELD) arranged along the plane (200), and then switching the voltage impressed on each of the plurality of electrodes (ELD) in accordance with a time interval required for producing dielectric polarization in the substrate plate.
In this case, by providing a first electrode section (210) having the plurality of first electrodes (ELD) arranged in a first direction, and a second electrode section (211) having the plurality of second electrodes (ELD) arranged in a second direction at right angles to the first direction, the substrate plate (P) can be positioned on the specific plane (200) in two-dimensional directions. Therefore, positioning of the substrate plate (P) can be carried out even more reliably.
In this case, the second electrode sections (211, 212) may be distributed in a direction at right angles to the second direction in separate groups. By so doing, the driving forces from the second electrode sections (211, 212) for the substrate plate (P) may be made to oppose each other, so as to provide a rotational force to correct the position of the substrate plate (P) in the rotation direction.
In this case, by providing an insulating member (203) may be disposed between the substrate plate (P) and the plane (200), dielectric polarization of the substrate plate (P) may be carried out in a stable manner.
In this case, by providing a gas supply apparatus for supplying a gas between the substrate plate (P) and the plane (200), levitation of the substrate plate (P) against the plane (200) may be carried out in a stable manner.
The present method for holding a substrate plate (P) on a holding surface (200) is used in association with the positioning method described above for positioning the substrate plate (P) on the holding surface (200). According to this method for holding the substrate plate (P), because the substrate plate (P) is positioned on the plane (200) using the electrostatic forces, processing time can be shortened compared to cases of positioning the substrate plate (P) in other positions.
Also, the present apparatus for holding a substrate plate (P) on a holding surface (200) is used in association with an apparatus (132) for positioning recited in above for positioning the substrate plate (P) on the holding surface (200). According to the apparatus for holding the substrate plate (P), it becomes possible to construct an apparatus having both functions of positioning and holding a substrate plate (P) so that an apparatus having both functions may be made more compact.
Also, the present method for exposure is used in association with a method described above for transporting a substrate plate (P) to a path of the illumination light (EL). In this case, the transport efficiency is improved, leading to improvement in the efficiency of overall manufacturing process. Further, the method for exposure includes positioning a substrate plate in a path of the illumination light using a method of positioning or a method of holding a substrate plate (P) described above. In this case, by suppressing the vibration accompanying the positioning operations, exposure precision of actual device structure is improved. Also, the present exposure apparatus includes a transport apparatus (H) described above for transporting a substrate plate (P) to a path of the illumination light (EL). Also, the present exposure apparatus includes a substrate positioning and holding apparatus (132) for positioning and holding a substrate plate (P) on the plane (200).
The present method for manufacturing a device includes a photolithographic step in which a method of exposure described above is applied. In this case, the present invention enables high precision fabrication of patterns on the device, and the precision of the manufactured device is improved. Also, the present device is manufactured by using an exposure apparatus described above.